Japanese Patent Laid-Open No. 63-23868 discloses biphenylmethylimidazole compounds which have an antagonistic action to angiotensin II and are useful as antihypertensives and therapeutic medicines for congestive cardiac incompetence. The publication discloses that a 4-bromomethylbiphenyl compound used as a synthetic intermediate for the biphenylmethylimidazole compounds is produced by bromination of a 4-methylbiphenyl compound with N-bromosuccinimide in a carbon tetrachloride solvent in the presence of dibenzoyl peroxide at a temperature not more than a reflux temperature.
Also, Japanese Patent Laid-Open No. 6-192170 discloses a method of using an azobis compound as a radical initiator while using a bromination agent similar to the above in order to solve the problems in yield and operability.
However, both of these methods have to employ expensive bromination agents such as N-bromosuccinimide. In the latter case where the yield is somewhat improved from the former case, the presence of the dibromo-product, which is formed as a by-product, causes to lower the selectivity of the monobromo-product to 85 or 90%, and the yield to 70 or 80%. Therefore, both methods cannot be considered as industrially advantageous production methods.